The oven draws 1100 w of power, and you have determined that it heats with an efficiency of 51%. using this information, determine the time t it would take to bring 240 ml of water from 25∘c to 100∘c . note that 4.2 j of energy is required to raise the temperature of 1.0 ml of water by 1.0∘c (the same as for the coffee above).

134.75935 seconds

Explanation:

m = Amount of water = 240 mL

c = Specific heat of water = 4.2 J/mL °C

=  Change in temperature =

t = Time taken

P = Power = 1100 W

E = Pt

Efficiency = 51 %

So, Energy = 0.51Pt

As energy is conserved

Q = 0

The it takes to raise the temperature is 134.75935 seconds

b.a device that inputs heat into a cool object

+15-35=-20

going in opposite directions